U.S. patent application number 12/403290 was filed with the patent office on 2009-09-17 for integrated catalyst.
Invention is credited to Dogan Ay, Steffen Jordan, Herbert Schlensker, Ingo Stumberg.
Application Number | 20090232686 12/403290 |
Document ID | / |
Family ID | 40953064 |
Filed Date | 2009-09-17 |
United States Patent
Application |
20090232686 |
Kind Code |
A1 |
Ay; Dogan ; et al. |
September 17, 2009 |
Integrated Catalyst
Abstract
The invention relates to an air compressor having a catalyst
that is disposed in a reception block. The reception block is
interposed between a valve block and a cylinder cover, comprises an
inlet port in the region of a valve block outlet port, and an
outlet port in the region of a cylinder head inlet port, so the
compressed air exiting the valve block outlet port flows through
said catalyst and through the outlet port into the cylinder
cover.
Inventors: |
Ay; Dogan; (Hannover,
DE) ; Jordan; Steffen; (Ronnenberg, DE) ;
Stumberg; Ingo; (Hannover, DE) ; Schlensker;
Herbert; (Leverkusen, DE) |
Correspondence
Address: |
MCCARTER & ENGLISH, LLP HARTFORD;CITYPLACE I
185 ASYLUM STREET
HARTFORD
CT
06103
US
|
Family ID: |
40953064 |
Appl. No.: |
12/403290 |
Filed: |
March 12, 2009 |
Current U.S.
Class: |
417/437 ;
417/243; 422/122 |
Current CPC
Class: |
F04B 39/12 20130101;
F04B 39/125 20130101; F04B 39/121 20130101; F04B 39/16
20130101 |
Class at
Publication: |
417/437 ;
417/243; 422/122 |
International
Class: |
A61M 1/00 20060101
A61M001/00; F04B 25/00 20060101 F04B025/00; B01J 19/00 20060101
B01J019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2008 |
DE |
10 2008 014 205.0 |
Claims
1. An air compressor with a catalyst disposed in a reception block,
said reception block being interposed between a valve block and a
cylinder cover, comprising an inlet port in the region of a valve
block outlet port and an outlet port in the region of a cylinder
head inlet port, so that the compressed air exiting the valve block
outlet port flows through said catalyst and through the outlet port
into the cylinder cover.
2. The air compressor as set forth in claim 1, further comprising a
piston and cylinder arrangement.
3. The air compressor as set forth in claim 2, further comprising a
cylinder block which comprises at least one cylinder for receiving
at least one piston.
4. The air compressor as set forth in claim 3, wherein the valve
block is interposed between the cylinder block and the reception
block.
5. The air compressor as set forth in any claim 1, wherein the
reception block further comprises a recess for the catalyst.
6. The air compressor as set forth in claim 5, wherein the catalyst
is pressed into the recess.
7. The air compressor as set forth in claim 6, further comprising
an intermediate plate for retaining the catalyst material in the
recess.
8. The air compressor as set forth in claim 1, wherein the catalyst
is configured to be an oxidation catalyst.
9. The air compressor as set forth in claim 1, wherein the air
compressor is configured to be water cooled and the existing water
channels are laid through the reception block.
10. The air compressor as set forth in claim 1, wherein the
catalyst is made from a foam-like cast metal that is coated with a
catalytically active material.
11. The air compressor as set forth in claim 10, wherein the
catalyst is made from aluminium as the carrier material.
12. The air compressor as set forth in claim 5, wherein the recess
is configured to be conical.
13. The air compressor as set forth in claim 5, wherein the air
compressor is an industrial air compressor.
14. Use of the air compressor as set forth in claims 1 for
providing compressed air on a vehicle.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to co-pending German
Patent Application No. DE 10 2008 014 205.0, filed Mar. 14, 2008,
which is hereby expressly incorporated by reference in its entirety
as part of the present disclosure.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an air compressor with a
catalyst disposed in a reception block.
[0003] Air compressors generate compressed air by drawing and
compressing ambient air. They are utilized in the industry and
often also on trucks in order to provide compressed air for the
brake system or for the vehicle spring or damper system. The
compressed gas is thereby almost inevitably contaminated with oil
aerosols and oil vapor, all the more so if the air compressors are
operated with oil lubrication. Due to the small amount of leakage
between pistons and cylinders, the oil aerosols and the oil vapor
are transported with the supplied compressed air into the
compressed air system. The amount of contamination thereby depends
on the operating conditions such as temperature, compressed air
volume flow or component tolerances.
[0004] For a plurality of applications, such type contamination is
undesirable or even unacceptable. Presently, no compressors are
known which are capable of generating oil-free compressed gases
without having to additionally process them. Although compressors
for oil-free compression of gas or compressed air are available,
the compressed air they generate still comprises at least small
amounts of, for example, organic impurities. This results, inter
alia, from the fact that the compressions absorb impurities from
ambient air. The oil contaminates and, as a result thereof, affects
the function of the components mounted downstream thereof. When the
compressed air, which has been used, is vented to the atmosphere,
this also has an impact on the environment.
[0005] For this reason, one usually utilizes filter systems mounted
downstream thereof which are to ensure appropriate quality of the
compressed air. Substantially, absorption filters made from
activated carbon are known, but they have a short life. One also
utilizes the catalytic combustion of the oil contained in the
compressed air, using what are referred to as oxidation catalysts.
Put simply, the oil, which is contained in the compressed air in
the form of hydrocarbon compounds (CH groups), is chemically broken
down to carbon dioxide (CO2) and water (H20) in an exothermic
reaction. This method is in particular known from the automotive
field and is utilized for both gas and diesel engines. In process
engineering, oxidation catalysts are also utilized for cleaning
contaminated exhausts.
[0006] U.S. Pat. No. 5,284,629 A describes a method of removing
compressor oil from compressed air wherein the compressed air is
led through a tank in which there is located a layer of an
oxidation catalyst. Metallic components selected from the group
consisting of platinum, palladium, nickel, cobalt, iron, rhodium,
manganese and copper are indicated as the materials used for
oxidation catalysts.
[0007] The document DE 100 08 609 C1 further describes a similar
method wherein a hopcalite material is utilized as the oxidation
catalyst. Hopcalite is the name for mixed oxidation catalysts
mainly consisting of manganese dioxide and copper(II) oxide. They
may also contain additional metal oxides such as cobalt oxide and
silver (I) oxide.
[0008] The document WO 00/66251 also describes an apparatus for
cleaning compressed air with the help of an oxidation catalyst
mounted downstream of an air compressor.
[0009] These systems are supplied with electrical energy in order
to achieve the required reaction temperature of the oxidation
catalyst. Moreover, they must be disposed as additional components
in the region of the air compressors, which means that they need
space and mounting expense in accordance therewith. Heat exchangers
are also needed as well as appropriate equipment for controlling
the electronics. In particular in case of smaller amounts of
compressed air, such type oxidation catalysts are disproportionally
expensive.
[0010] The document EP 136 37 21, as well as the document DE 199 02
052 C2, describe the integration of oxidation catalysts in the air
compressor itself. According to DE 199 02 052 C2, the oxidation
catalyst is embedded in a horizontal portion of a throttle output
and extends as far as the outer wall side of the cylinder head. The
apparatus according to EP 136 37 21 is similar, with the oxidation
catalyst being also disposed in the outlet of a cylinder. The
apparatus described in these printed documents require that the
oxidation catalyst material be mounted in the outlet channel. For
this purpose, it is necessary to change the construction of the
cylinder head or of the outlet channel since otherwise the quantity
of oxidation catalyst material will not suffice. Moreover, the
oxidation catalyst is difficult to maintain or replace. Finally, it
seems unavoidable to rebuild the cylinder.
BRIEF SUMMARY OF THE INVENTION
[0011] It is the object of the present invention to provide an air
compressor with a catalyst that reduces the oil contained in the
compressed air to a very low amount. Thereby, as far as possible,
the air compressor is intended to be at low cost to manufacture and
to maintain. In particular, the apparatus should be of the smallest
possible dimensions.
[0012] In accordance with the invention, the solution to this
object is achieved with an air compressor having a catalyst
disposed in a reception block, said reception block: (i) being
interposed between a valve block and a cylinder cover; (ii)
comprising an inlet port in the region of a valve block outlet
port; and (iii) comprising an outlet port in the region of a
cylinder head inlet port, so the compressed air exiting the valve
block outlet port flows through the catalyst and through the outlet
port into the cylinder cover.
[0013] The apparatus of the invention involves several improvements
to prior art. The catalyst, preferably an oxidation catalyst, is
not disposed directly in the compression chamber or in the outlet
channel placed downstream thereof like in prior art, but is located
in an intermediate element configured to be a reception block and
located between the valve block and the cylinder head. As a result,
a commercially available air compressor, preferably a piston
compressor, may be readily modified for using the integrated
catalyst. It is merely necessary to detach the cylinder cover from
the cylinder block, to insert the reception block with the catalyst
and to connect again the cylinder cover with the cylinder block.
Only the screws and gaskets need to be adapted. With the
appropriate gaskets, the reception block fits snugly between the
existing elements of the air compressor.
[0014] As opposed to the prior art arrangement, the arrangement of
the invention also involves that the already existing component
parts of the air compressor will not be subjected to higher
loads.
[0015] Through the proximity of the reception block to the
compression chamber, the high temperatures anyway achieved by
virtue of compression, are made use of for optimal operation of the
catalyst. When air is being compressed, high compression
temperatures of more than 300.degree. C. occur due to the way the
system operates, said temperatures being sufficient for the
catalyst to react, so that additional heating is not necessary.
[0016] Preferably, the catalyst is disposed in a recess within the
reception block, said recess being configured such that the space
that is available with the given restrictions such as the cooling
channels is made use of in the best possible way to achieve the
largest possible catalyst volume.
[0017] In particular, the integration of the catalyst in an air
compressor with two cylinders in a water-cooled implementation as
it is usually utilized in utility vehicles is readily possible. In
air cooled machines it may also be readily inserted if the
reception block is devised accordingly. In case of water cooling,
the water channels existing in the cylinder are laid through the
reception block so that the cooling flow needs not be
interrupted.
[0018] As a substrate for a catalytic active coating, one may use,
for example, perforated, wound and then soldered sheet steel
materials, ceramic blocks with through holes, foam-like substrate
discs made from ceramic materials, wire knits of various design
and/or granulates made for their major part of ceramic
materials.
[0019] As a base for catalytic active coatings, one may use, for
example, copper oxide, iron oxide, copper manganese oxide,
palladium, platinum and/or gold.
[0020] The substrates and the catalytically active coatings are
only mentioned by way of example and are not understood to limit
the materials that may be utilized within the scope of the
invention. The choice of the substrate and of the catalytic coating
depends, in particular, on the purpose of utilization.
[0021] As a substrate, it has been found particularly advantageous
to use a form-fitting, molded, sponge-like metal body coated with a
catalytically active material. This construction is also extremely
resistant to vibrations.
[0022] The catalyst is pressed into a recess or a groove of the
reception block that is adapted to the design of the substrate.
During this pressing process, the catalyst is slightly deformed so
that it is firmly retained in the recess or groove. A major
advantage is that the discrete component parts must not be machined
with the greatest possible accuracy; it is sufficient if it is
molded for coarse registration fit, which is lower cost. The
reception block is then mounted, together with the fixed catalyst,
with corresponding gaskets between the valve block and the cylinder
cover. As already discussed, other forms of the substrate may also
be envisaged; instead of the foam-like cast metal one may also use
a making with several plates which are cut to shape by means of
water jet or laser and which are stacked one above the other in the
receiving receptacle after coating. For passage of the compressed
air, such type plates may for example be made from a grid material
or a knit material. Another variant consists in using granulate as
the catalyst material, which is also pressed into the receiving
receptacle.
[0023] Aluminum is particularly suited as a foam-like catalyst
material since it is light, ductile and weldable. A braided
stainless steel may also be used.
[0024] The recess in the reception block is configured to be
slightly conical for ease of demolding.
[0025] It may further be envisaged to configure the reception block
itself to be closed in the direction of the cylinder head except
for the passageways needed for compressed air and at need for water
cooling; but it may also be envisaged to use a gasket or an
intermediate plate for closing the recess in the direction of the
cylinder head.
[0026] The present invention will be discussed in closer detail by
way of a preferred exemplary embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 shows a perspective side view of an air compressor of
the invention.
[0028] FIG. 2 shows the air compressor of FIG. 1 in a side view, in
partial section.
[0029] FIG. 3 shows component parts of the air compressor of FIG. 1
in an exploded view.
[0030] FIG. 4 shows a catalyst carrier of the invention.
[0031] FIGS. 5 to 9 show implementations of the reception block of
the invention for receiving the catalyst.
DETAILED DESCRIPTION OF THE INVENTION
[0032] FIGS. 1 and 2 show an air compressor 20 of the invention, in
which there is integrated a reception block 23. A piston compressor
is shown by way of example. A crankcase 24 is adjoined with a drive
shaft to a motor that has not been illustrated herein. The
crankcase 24 is adjacent a cylinder block 28. Inside said cylinder
block 28 there are located two pistons 30 in the exemplary
embodiment shown. On the cylinder block 28, there are further
located a valve block 32 with a cooling water outlet 34. The
reception block 22 is interposed between the valve block 32 and a
cylinder cover 36, said cylinder cover 36 comprising an intake air
inlet 38, a cooling water inlet 40 and a compressed air outlet 42.
Further details of the air compressor 20 will not be discussed in
closer detail herein since they correspond to commercially
available air compressors for utility vehicles.
[0033] Advantageously, the reception block 22 is merely inserted
between the cylinder cover 36 and the valve block 32, the air
compressor 20 hardly needs to be changed or not at all. Only the
screws 44 connecting the cylinder cover 36 and the cylinder block
28 must be adapted. As a result, it is possible to readily retrofit
existing air compressors with the reception block 22.
[0034] FIG. 3 shows the upper part of the air compressor, which is
built substantially in layers, said upper part comprising the
already mentioned components valve block 32, reception block 22 and
cylinder cover 36. As already explained, the reception block 22 is
bounded by the valve block 32 and the cylinder cover 36. Between
the valve block 32 and the reception block 22 there is provided a
valve block gasket 46, between the reception block 22 and an
intermediate plate 48 there is provided a reception block gasket 50
and between the intermediate plate 48 and the cylinder cover 36, a
cylinder cover gasket 52. The gaskets 46, 50, 52 comprise ports for
feeding cooling water and compressed air therethrough.
[0035] According to an advantageous implementation of the
invention, the intermediate plate 48 mentioned is provided for
retaining the catalyst material in a recess 54 of the reception
block 22. The reception block gasket 50 serves for sealing the
recess 54.
[0036] A first variant of the catalyst 56 is shown in FIG. 4. In
accordance with the invention, the catalyst is formed from a
foam-like cast metal that is coated with a catalytically active
material.
[0037] Advantageously, the course and shape of the recess 54 is
adapted to the valve block 32 and to the cylinder cover 36 in a
manner which makes it possible to best lead the compressed air and
simultaneously the cooling water therethrough. The existing space,
with its given limitations, is best made use of as a result thereof
and one achieves the largest possible catalyst volume. This design
may be very permissive and low cost thanks to what is referred to
as primary shaping.
[0038] FIG. 5 shows a first embodiment of the reception block 22
with a recess 54 for receiving the catalyst material. The reception
block with the catalyst material 56 disposed in the recess 54 is
illustrated in FIG. 6. As can be seen, the catalyst material 56
substantially completely fills out the recess 54.
[0039] In FIG. 7, there is illustrated another embodiment of the
reception block 22, which comprises recesses for rod-shaped,
advantageously cylindrical, catalyst elements 56. The ports
provided in the reception block 22 are closed with closing plugs
57. FIG. 8 shows the reception block 22 shown in FIG. 7 in a
sectional view.
[0040] In FIG. 9, there is illustrated another embodiment of the
reception block 22. In this embodiment, there are provided recesses
for receiving disc-shaped catalyst elements 56.
[0041] Those skilled in the art will appreciate that the invention
described herein above, and in particular in accordance with the
advantageous exemplary embodiments, makes it possible to integrate
a catalyst in the cylinder head of a compressor whilst optimizing
the mounting space. Modular construction, which makes it possible
on the one side to complement existing air compressor concepts by
introducing the reception block, is hereby advantageous. Moreover,
replacement of the catalyst material is made easy as one replaces
the reception block. As a result, the air compressor of the
invention is particularly easy to maintain.
[0042] Another advantage is obtained, which is that the catalyst
material is disposed in a region of the air compressor in which the
quite high air temperatures of the cylinder head are available,
which increases the efficiency of the catalyst and makes the use of
additional heating devices superfluous.
[0043] The invention is not limited to the exemplary embodiment
described, but also includes other embodiments which will become
apparent from the disclosed context.
* * * * *